This invention relates to attachments for sewing machines for forming ruffles in fabrics. There are many kinds of sewing machine attachments which enable ruffling of fabrics. However, these conventional types of attachments have some drawbacks which will hereinafter be explained.
A lever mounted shiftably on an attachment body is lifted upward and downward by means of a needle-bar of a sewing machine to which the end of the lever is removably fastened. With the upward and downward shifting of the lever, a ratchet wheel mounted on the end of the attachment body together with a connector stand is rotated in a predetermined direction by means of a ratchet of a ratchet gear feed plate mounted on the lever. As the ratchet wheel is thus rotated, the connector stand or plate having at its lower end a guide plate provided with a feed plate is shifted horizontally forward and backward, whereby the feed plate under which is disposed a fabric is shifted forward and backward while pressingly contacting the surface of the fabric with the result that a successive formation of ruffles on the fabric is obtained.
Generally speaking, the upward and downward strokes of a needle-bar of a sewing machine may be arranged differently according to the type of sewing machine to be used, while a ruffler attachment provided with a guide plate and a feed plate is designed to undergo forward and backward shifting by a fixed or predetermined distance. Therefore it is usual that a ruffler attachment having a feed plate which undergoes a particular predetermined shifting is to be chosen to be used with a particular sewing machine provided with a needle-bar which functions to shift upward corresponding with the particular predetermined shifting distance of the ruffler. In FIG. 6, reference character P indicates a needle piercing position of the fabric 48 and P' shows a folded end of the fabric 48. Whenever the upward shifting distance of the needle-bar 41 provided with a needle 41a is performed to correspond with the predetermined shifting distance of a feed plate, normal even stitches 49 are formed in the fabric 48. However, when the upward shifting distance of the needle-bar 41 is longer than the predetermined shifting distance of the feed plate, an end P" of folded fabric is formed away from the needle piercing position P as shown in FIG. 6 and irregular loop stitches 50 are formed, as shown in FIG. 7(A).